As semiconductor technology advances beyond 130 nm and 90 nm technology towards 65 nm, 45 nm, 32 nm, and even beyond, the electrostatic discharge (ESD) protection for input/output (I/O) pads and supply clamps becomes more challenging. This is especially true for silicon-on-insulator (SOI) technology, which is expected to be preferable over bulk technology for the new process nodes. An ESD event refers to a phenomenon of electrical discharge of a current (positive or negative) for a short duration during which a large amount of current is provided to a semiconductor structure.
Present-day ESD protection circuits present a number of drawbacks, particularly when used with SOI technology. Some ESD protection circuits suffer from high leakage current and high capacitive loading. Other ESD protection circuits, such as those on SOI substrates, may exhibit lower leakage current and lower capacitive loading, but require thin SOI films that limit the device's ESD capability due to high self-heating, which, in turn, lowers the failure current under ESD stress.
Accordingly, it is desirable to provide an ESD protection device that exhibits low leakage and low capacitive loading. It also is desirable to provide an ESD protection device that enables a reduction in size of the device. In addition, it is desirable to provide a method for protecting a semiconductor structure from an ESD event using an improved ESD protection device. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.